Kyphoplasty system and method

ABSTRACT

A kyphoplasty system disclosed herein includes various instruments which can be selectively used to perform a kyphoplasty operation on a patient. For example, in some embodiments the kyphoplasty system includes an inflation plunger that is used to deliver a balloon inflation medium to enlarge an implantable balloon device. Further, some embodiments described herein include a connection system between the implantable balloon device and its delivery shaft that is simple to construct and easy to use. For example, in some embodiments one or more sutures are used to releasably connect the implantable balloon device to its delivery shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 17/157,165, filed on Jan. 25, 2021 (now U.S. Pat. No. 11,103,290),the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

This document generally relates to kyphoplasty and/or otherinterventional spinal procedures.

BACKGROUND

Kyphoplasty is a minimally invasive surgical procedure for treatment ofpain caused by vertebral body compression fractures. Typically, theprocedure involves insertion of one or more coaxial 8-10 gauge boneintroducer needles under fluoroscopic guidance into one or morefractured vertebral bodies utilizing a bipedicular, unipedicular, orextrapedicular approach. In some approaches, after a bone introducerneedle is in place, the inner portion of the bone introducer needle isremoved and the outer portion of the bone introducer needle remains as aguide and support for the remaining procedure. Through the boneintroducer needle, a drill and curette are utilized for cavity creationin the vertebral body. In many cases, after the cavity is created, thedrill and curette are removed, and a deflated balloon is inserted intothe cavity of the vertebral body. The balloon is then inflated, forexample, by injecting a solution into the balloon, thereby expanding thedrilled cavity into a desired size within the vertebral body. When thecavity is expanded to the desired size, the balloon is deflated andremoved from the vertebral body. Usually in such cases, a bone filler isadvanced into the vertebral body, and the expanded cavity is filled withcement.

SUMMARY

Some embodiments described herein include a kyphoplasty system. Thekyphoplasty system includes a multi-functional device that simplifiescavity creation and filling processes, with improved height restorationof a fractured vertebral body. For example, the kyphoplasty system canbe configured to maintain a desired anatomic height (e.g., after aballoon is inserted to expand a vertebral body cavity to a desiredheight) before and during the delivery of cement to the expanded cavity.Further, in some examples described herein, the kyphoplasty system canemploy an instrument that is configured to both expand the vertebralbody cavity to the desired anatomic height (e.g., using a balloon) andalso fill the vertebral body cavity with cement.

Embodiments of the multi-functional device disclosed herein integrate aballoon device with a bone filler device. Some such embodiments areconfigured as a single unit which can be detachably coupled to a distalend of an elongated shaft of a kyphoplasty device. The multi-functionaldevice can be introduced into a fractured vertebral body by advancingthe shaft of the kyphoplasty device, with the multi-functional devicecoupled at the distal end, into the fractured vertebral body. The shaftwith the multi-functional device can be inserted into the vertebral bodycavity of a fractured vertebral body through, for example, a boneintroducer needle or sheath. While inserted into the vertebral bodycavity, the multi-functional device then advantageously allows bothinflating the balloon and injecting bone filling substance into thefractured vertebral body cavity. Such balloon inflation and bone fillerinjection can be performed sequentially, simultaneously, oralternatingly while the multi-functional device remains in the vertebralbody cavity.

The balloon can be configured to form various inflated shapes, such asspheres, cylinders, cubes, diamonds, prisms, and other multifaceted 3-Dshapes. For example, multifaceted shapes, such as diamond shapes, canincrease surface area contact. In addition or alternatively, thekyphoplasty systems described herein can include multiple sets of shaftsand dual port devices that are operated simultaneously or in sequence.

Some embodiments of the technologies described herein include aconnection system that allows compact, easy, and reliable engagementbetween instruments in the kyphoplasty system or other interventionalprocedures. For example, the connection system can be sized sufficientlysmall and provide minimum interference between different sets ofinstruments that are arranged together in a dense area where manyinstruments are introduced into the patient. That way, multipleinstruments may be used in a small area of the patient body at the sametime while also reducing obstructions in the working space locatedexterior to the patient. For example, the kyphoplasty system in someembodiments herein may use a plurality of bone introducer needles toaccess a plurality of vertebral bodies that are closely arranged, andeach bone introducer needle may include a needle (e.g., a cannula) and ahead (e.g., an inner connector) fixed to an end of the needle.Preferably, the head of the bone introducer needle and/or each exteriorconnector are sized sufficiently small and provide minimum interferencebetween different sets of instruments that are arranged together in adense area where many instruments are introduced into the patient.

Some embodiments of the technologies described herein include anintroducer needle with a backflow prevention device. Embodiments of thebackflow prevention device of the introducer needle include a one-wayvalve arranged in a hub of the introducer needle. For example, theintroducer needle includes a needle and a hub mounted at an end of theneedle. The hub defines an interior space being in fluid communicationwith a canal of the needle, and further includes a one-way valvearranged within the interior space and configured to prevent backflow ofblood or body fluids (e.g., flow in a direction away from a patient'sbody) when, for example, a biopsy needle is removed from the patient'sbody through the introducer needle. In addition, the hub can provides acoupling mechanism (e.g., a luer lock) for an instrument (e.g., acoaxial biopsy device).

In a first aspect, this disclosure is directed to a kyphoplasty systemthat includes a balloon device and an inflation plunger. The balloondevice defines a first lumen and includes a balloon implant membercomprising a balloon mounted on a balloon shaft. The balloon device alsoincludes a balloon member delivery shaft. The balloon implant member isreleasably attached to a distal end portion of the balloon memberdelivery shaft. The inflation plunger defines a second lumen. Theinflation plunger is configured to slidingly engage in the first lumenand to convey, via the second lumen, an inflation medium to inflate theballoon.

Such a kyphoplasty system may optionally include one or more of thefollowing features. A distal end portion of the inflation plunger maydefine one or more inflation apertures that allow the inflation mediumto exit the second lumen. The distal end portion of the inflationplunger may include a first seal located proximal of the one or moreinflation apertures. The distal end portion of the inflation plunger mayinclude a second seal located distal of the one or more inflationapertures. The first and second seals may seal against a wall of thefirst lumen. The balloon implant member may also include one or moreone-way valves arranged to allow flow of the inflation medium to inflatethe balloon and to prevent the inflation medium from exiting theballoon. In some embodiments, the one or more one-way valves includes atleast one of a one-way flap valve or a one-way sleeve valve. The balloonimplant member may be releasably attached to the distal end portion ofthe balloon member delivery shaft by one or more sutures. In someembodiments, the one or more sutures includes two sutures that are eachlooped through a respective opening of two openings defined by theballoon shaft.

In another aspect, this disclosure is directed to a method forperforming a kyphoplasty procedure. The method includes: inserting aballoon implant member comprising a balloon mounted on a balloon shaftinto a vertebral body cavity and inflating the balloon. The balloonimplant member may be releasably attached to a distal end portion of aballoon member delivery shaft such that a lumen defined by the balloonmember delivery shaft and a lumen defined by the balloon shaft adjoin todefine a first lumen. The inflating the balloon is performed byinjecting an inflation medium into a second lumen defined by aninflation plunger that is within the first lumen.

Such a method for performing a kyphoplasty procedure may optionallyinclude one or more of the following optional features. The method mayalso include, prior to inserting the balloon implant member into thevertebral body cavity, advancing a bone introducer needle adjacent tothe vertebral body cavity. The balloon implant member may be insertedinto the vertebral body cavity through the bone introducer needle. Themethod may also include, after advancing the bone introducer needleadjacent to the vertebral body cavity and before inserting the balloonimplant member into the vertebral body cavity, advancing a space-makingballoon through the bone introducer needle and inflating thespace-making balloon within the vertebral body cavity. The method mayalso include, after inflating the balloon, retracting the inflationplunger from the first lumen. The method may also include, afterretracting the inflation plunger from the first lumen, injecting fillermaterial into the vertebral body cavity external to the balloon implantmember. In some embodiments, the filler material is injected into thevertebral body cavity external to the balloon implant member via thefirst lumen. In particular embodiments, the filler material is injectedinto the vertebral body cavity external to the balloon implant membervia an elongate needle within the first lumen. The method may alsoinclude, after inflating the balloon, detaching the balloon implantmember from the balloon member delivery shaft such that the balloonimplant member remains in the vertebral body cavity. The detaching mayinclude removing one or more sutures by which the balloon implant memberis releasably attached to the distal end portion of the balloon memberdelivery shaft during the inserting.

The apparatuses, systems, devices, and techniques described herein mayprovide one or more of the following advantages. Some embodimentsdescribed herein include a kyphoplasty system that includes amulti-functional device providing both balloon inflation and bonefilling functionalities together in a single unit, thereby simplifying akyphoplasty procedure. The dual port device improves height restorationof a fractured vertebral body by the balloon inflation, and permits forthe vertebral body cavity to be filled with the bone filler withoutlosing the restored height.

Further, some embodiments described herein include a connection systembetween the implantable balloon device and its delivery shaft that issimple to construct and easy to use. For example, in some embodimentsone or more sutures are used to releasably connect the implantableballoon device to its delivery shaft. The one or more sutures areadvantageously low-profile, as well as easy and intuitive to use. Thatis, clinicians can easily detach the implantable balloon device from itsdelivery shaft by withdrawing the one or more sutures from engagementwith the implantable balloon device.

Moreover, some embodiments described herein include an inflation plungerthat is used to deliver a balloon inflation medium to enlarge theimplantable balloon device. As described further below, the design andfunctionality of the inflation plunger advantageously allows for acompact and concise overall design of the kyphoplasty systems describedherein.

The details of one or more implementations are set forth in theaccompanying drawings and the description below. Other features andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the clinical use of an example kyphoplasty system that isbeing used to restore a fractured vertebral body.

FIG. 2 schematically illustrates the implantation of an examplekyphoplasty apparatus to restore a fractured vertebral body.

FIG. 3 schematically illustrates the vertebral body of FIG. 2 afterrestoration using the kyphoplasty systems described herein.

FIG. 4 is a flowchart that describes an example kyphoplasty method inaccordance with some embodiments.

FIG. 5 illustrates an example kyphoplasty system in a deliveryconfiguration.

FIG. 6 is a close-up view of a distal end portion of the kyphoplastysystem of FIG. 5 .

FIG. 7 illustrates an example inflation plunger component of thekyphoplasty systems described herein.

FIG. 8 is a longitudinal cross-section view of the inflation plunger ofFIG. 7 .

FIG. 9 illustrates the kyphoplasty system of FIG. 5 with the balloonmember in an expanded configuration.

FIG. 10 is a longitudinal cross-section view of the kyphoplasty systemof FIG. 9 .

FIG. 11 is a close-up view of the distal end portion of the kyphoplastysystem of FIGS. 7 and 8 .

FIG. 12 illustrates a distal portion of an example kyphoplasty systembeing used to deliver vertebral body filler material.

FIG. 13 illustrates an example balloon implant delivery shaft inaccordance with some embodiments.

FIG. 14 is a longitudinal cross-section view of the balloon implantdelivery shaft of FIG. 13 .

FIG. 15 illustrates the detachment of a balloon implant member from itsdelivery shaft.

FIG. 16 illustrates the balloon implant member of FIG. 15 in isolationafter detachment from its delivery shaft.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 illustrates an example kyphoplasty system 100 being used by apractitioner P to perform a kyphoplasty procedure in a surgical theater102. The patient 1 is laying prone on a prone table mat 130 during thekyphoplasty procedure.

In the surgical theater 102, the kyphoplasty system 100 can be used inconjunction with an image scanner 180, such as a C-arm fluoroscopymachine, and a display device 182 configured to receive images (e.g.,still and/or video images) from the image scanner 180 and to display theimages to assist a practitioner P with visualization during thekyphoplasty procedure. In some embodiments, one or more components ofthe kyphoplasty system 100 can include one or more radiopaque markers.For example, in some embodiments the kyphoplasty system 100 includes animplantable balloon member that can include one or more radiopaquemarkers.

While the kyphoplasty system 100 and procedure is described in greaterdetail below, briefly the kyphoplasty procedure includes advancing abone introducer needle toward a vertebral body of the patient 1. Whilethe bone introducer needle is in place, the inner portion of the boneintroducer needle is removed and the outer portion of the boneintroducer needle remains as a guide and support for the remainingprocedural steps.

Through the bone introducer needle, a drill and curette are utilized forcavity creation in the vertebral body. In many cases, after the cavityis created, the drill and curette are removed, and a deflated balloon isinserted into the cavity of the vertebral body. The balloon is theninflated, for example, by injecting a solution or filler material (e.g.,bone cement) into the balloon, thereby expanding the drilled cavity intoa desired size within the vertebral body and thereby restoring theheight of the vertebral body. When the vertebral body cavity is expandedto the desired size by the inflated balloon, a bone filler (e.g., bonecement) is injected into the vertebral body cavity space that isexternal to the balloon. When the expanded cavity is sufficiently filledwith the bone filler material, the balloon is then detached and leftwithin the restored vertebral body, and the other components of thekyphoplasty system 100 are retracted from the patient 1.

FIG. 2 schematically illustrates a distal end portion of the kyphoplastysystem 100 partially within a vertebral body 10, as per the kyphoplastyprocedures described herein. The kyphoplasty system 100 includes aballoon device 120 that is advanced into a body cavity 12 of thevertebral body 10 via an introducer needle 110 (shown in longitudinalcross-section).

The balloon device 120 includes an expandable balloon implant member 122which is positioned within the vertebral body cavity 12. The balloonimplant member 122 is releasably attached to a balloon member deliveryshaft 124. As described further below, a lumen of the balloon memberdelivery shaft 124 is used to deliver bone filler material (e.g., bonecement) into the expandable balloon implant member 122 and into thevertebral body cavity 12 external to the expanded balloon implant member122.

As schematically depicted in FIG. 3 , after the bone filler material isinjected into the expandable balloon implant member 122 and into thevertebral body cavity 12, the balloon member delivery shaft 124 is thendetached from the balloon implant member 122. The balloon implant member122 is left implanted within the restored vertebral body cavity 12 ofthe vertebral body 10. While in the depicted scenario a single balloonimplant member 122 is implanted within the restored vertebral bodycavity 12, in some cases two balloon implant members 122 are implantedwithin the restored vertebral body cavity 12.

This ends the brief summary description of the kyphoplasty proceduresand systems disclosed herein. Additional details regarding thekyphoplasty system 100 and the kyphoplasty procedures performed usingthe kyphoplasty system 100 will now be provided in reference to FIGS.4-16 .

FIG. 4 provides a flowchart of an example balloon kyphoplasty procedure200. The kyphoplasty procedure 200 utilizes the kyphoplasty systems 100described herein to treat a fractured vertebra.

In step 210, a bone introducer needle (which can also be referred to asa sheath or trocar) is advanced toward the fractured vertebra of thepatient under x-ray fluoroscopy guidance. The bone introducer needledefines a lumen through which various instruments of the kyphoplastysystem 100, as described further below, can be advanced to treat thefractured vertebral body of the patient. In some embodiments, theintroducer needle includes a backflow prevention device configured toprevent backflow of blood or body fluids through the needle.

In step 220, a bone drill is advanced through the lumen of theintroducer needle toward the fractured vertebral body. The bone drill isthen rotatably driven to create an opening to access the vertebral bodycavity. Afterwards, in some cases the introducer needle is then advancedfarther, through the opening created by the bone drill. The bone drillcan also be used to create an initial open void inside of the vertebralbody. The bone drill can then be retracted and removed from the lumen ofthe introducer needle.

In optional step 230, a high-pressure space-making balloon can beadvanced through the lumen of the introducer needle and into thevertebral body cavity. In some cases, the high-pressure space-makingballoon can be an 800 psi balloon, a 1000 psi balloon, a 1200 psiballoon, and the like, without limitation. The space-making balloon canthen be inflated. The inflation of the space-making balloon elevates thefractured vertebra to its pre-fracture height, and creates a larger voidin the vertebral body cavity. The space-making balloon can then bedeflated. Then, the space-making balloon can be retracted and removedfrom the lumen of the introducer needle.

In step 240, a balloon device of the kyphoplasty systems 100 describedherein can be advanced through the lumen of the balloon deviceintroducer needle and into the vertebral body cavity. The balloon memberof the balloon device is deflated and configured in a low-profiledelivery configuration during this step.

FIGS. 5 and 6 depict an example balloon device 120 of the kyphoplastysystems 100 described herein. The balloon device 120 is deflated andconfigured in a low-profile delivery configuration, and is positionedwithin the lumen of an introducer needle 110 (shown transparently). Theballoon device 120 includes a balloon implant member 122 and a balloonmember delivery shaft 124. The balloon implant member 122 is releasablycoupled to a distal end portion of the balloon member delivery shaft124. As described further below, one or more removable sutures 160 (FIG.6 ) can be used to releasably couple the balloon implant member 122 tothe balloon member delivery shaft 124.

The balloon implant member 122 and the balloon member delivery shaft 124each define a lumen. While the balloon implant member 122 is releasablycoupled to the balloon member delivery shaft 124, the lumens of theballoon implant member 122 and the balloon member delivery shaft 124 areadjoining so as to function as a single lumen.

Still referring to FIG. 4 , in step 250 an inflation plunger that ispositioned in the lumens of the balloon implant member 122 and theballoon member delivery shaft 124 is used to inflate the balloon implantmember 122. This inflation of the balloon implant member 122 is executedwhile the balloon implant member 122 is located in the vertebral bodycavity.

FIGS. 7 and 8 depict an example inflation plunger 140 of the kyphoplastysystems 100 described herein. The inflation plunger 140 includes a shaft142 that defines a lumen 143. A distal end portion of the shaft 142defines one or more inflation apertures 144. The inflation apertures 144are openings to the lumen 143. In this example, two inflation apertures144 are included in the inflation plunger 140.

Two or more seals 146 are coupled to the distal end portion of the shaft142. In the depicted example, two seals 146 are included. In someembodiments, the seals 146 can be made of an elastomeric material suchas, but not limited to, silicone or urethane. In some embodiments, eachseal of the seals 146 is seated in a complementary groove 147 defined bythe outer diameter of the distal end portion of the shaft 142.

The inflation apertures 144 are positioned between the seals 146. Thatis, a first seal of the two or more seals 146 is located proximal of theinflation apertures 144, and a second seal of the two or more seals 146is located distal of the inflation apertures 144.

As stated above, the inflation plunger 140 is advanced through thelumens of the balloon implant member 122 and the balloon member deliveryshaft 124.

FIGS. 9 and 10 depict the inflation plunger 140 within the lumens of theballoon implant member 122 and the balloon member delivery shaft 124.The balloon implant member 122 is still not inflated in thisarrangement.

FIG. 11 depicts the injection of inflation medium into the balloonimplant member 122 using the inflation plunger 140, as per step 250 ofthe balloon kyphoplasty procedure 200 (FIG. 4 ). This causes a balloon121 of the balloon implant member 122 to expand within the vertebralbody cavity (see also FIG. 2 ).

To assist in the understanding of how step 250 takes place, additionalinformation regarding structural details of the balloon implant member122 will now be explained. The balloon implant member 122 includes theballoon 121 that is fixedly attached to a balloon shaft 123. The balloonshaft 123 defines the lumen of the balloon implant member 122 that isaligned with the lumen of the balloon member delivery shaft 124. Theballoon shaft 123 defines one or more apertures 127. The one or moreapertures 127 provide fluid communication between the lumen of theballoon implant member 122 and the interior of the balloon 121.Accordingly, inflation medium can pass into the interior of the balloon121 via the one or more apertures 127 of the balloon shaft 123.

The balloon implant member 122 also includes one or more one-way valves129. The one or more one-way valves 129 are positioned between the oneor more apertures 127 and the interior of the balloon 121. Accordingly,the one or more one-way valves 129 allow flow of the inflation mediuminto the balloon 121 (to inflate the balloon 121), but prevent the flowof the inflation medium in the opposite direction. This means that theinflation medium that enters the interior of the balloon 121 stays inthe interior of the balloon 121. In some embodiments, the one or moreone-way valves 129 may be a sleeve made of a flexible material such as,but not limited to, silicone or urethane. Accordingly, the one or moreone-way valves 129 may be referred to as sleeve valves. In someembodiments, the one or more one-way valves 129 may include displaceableflap members that open to allow flow into the interior of the balloon121, and that close when the flow is stopped. Other types of one-wayvalves 129 can also be utilized.

The inflation medium is injected by the practitioner P (FIG. 1 ) intothe lumen 143 of the inflation plunger 140. In some cases, the balloon121 is filled to about 200 psi, or in a range from about 150 psi toabout 250 psi, without limitation. In some cases, the inflation mediumthat is injected into the balloon 121 is a type of solidifying liquidsuch as orthopedic cement or bone cement (e.g., polymethyl methacrylate,calcium phosphate, magnesium phosphate, amorphous magnesium phosphate,etc.). In some cases, a contrast bone cement can be used as theinflation medium that is injected into the balloon 121.

The inflation medium flows distally through the lumen 143 of theinflation plunger 140 and exits the inflation plunger 140 via the one ormore apertures 144 (FIGS. 7 and 8 ).

Still referring to FIG. 11 , the two or more seals 146 of the inflationplunger 140 are in contact with the inner wall of the balloon shaft 123.Accordingly, a confined space exists between the outer wall surface ofthe inflation plunger 140, the inner wall surface of the balloon shaft123, and between the two or more seals 146. The one or more apertures144 of the inflation plunger 140 serve as the inlet(s) to the confinedspace. The one or more apertures 127 of the balloon shaft 123 serve asthe outlet(s) from the confined space.

Accordingly, the balloon 121 is inflated as follows. The inflationmedium is injected into the lumen 143 of the inflation plunger 140. Theinflation medium flows distally in the lumen 143 of the inflationplunger 140 and exits the inflation plunger 140 via the one or moreapertures 144 to enter the confined space. The inflation medium exitsthe confined space via the one or more apertures 127 of the balloonshaft 123, passes through the one or more one-way valves 129, and entersthe interior of the balloon 121. This completes step 250 of the balloonkyphoplasty procedure 200 illustrated in FIG. 4 .

In step 260 of the balloon kyphoplasty procedure 200 illustrated in FIG.4 , the inflation plunger 140 is retracted out of the lumens of theballoon shaft 123 and the balloon member delivery shaft 124. The lumensof the balloon shaft 123 and the balloon member delivery shaft 124(which together comprise the lumen of the balloon device 120) becomeunobstructed when the inflation plunger 140 is retracted.

Still referring to FIG. 4 , in step 270 of the balloon kyphoplastyprocedure 200 filler material (e.g., orthopedic cement as describedabove) is injected into the vertebral body cavity through the lumen ofthe balloon device 120. For example, as depicted in FIG. 12 , in someembodiments the distal end of the balloon shaft 123 is open and thefiller material can exit the lumen of the balloon device 120 therefrom.Upon exiting the lumen of the balloon device 120, the filler materialenters the vertebral body cavity 12, exterior to the balloon 121 (e.g.,as depicted in FIG. 3 in comparison to FIG. 2 ).

In some cases, the performance of step 270 includes the use of anelongate needle (e.g., a 13 gauge needle) to inject the filler material.That is, an elongate needle can be advanced into the lumen of theballoon device 120 and then the filler material can be ejected from theneedle such that the filler material enters the vertebral body cavity12, exterior to the balloon 121.

In step 280 of the balloon kyphoplasty procedure 200, the balloon memberdelivery shaft 124 is detached from the balloon implant member 122.Thereafter, the balloon member delivery shaft 124 is retracted from thepatient while the balloon implant member 122 remains implanted in thevertebral body cavity 12 (e.g., as depicted in FIG. 3 ).

Various kinds of selectively releasable mechanisms can be used tofacilitate the detachment of the balloon member delivery shaft 124 fromthe balloon implant member 122. For example, in some embodiments a snapfit connection, a threaded connection, a collet mechanism, abayonet-style connection, and the like, can be used, without limitation.In some embodiments, the balloon member delivery shaft 124 is releasablyattached to the balloon implant member 122 by one or more removablesutures 160 as depicted in FIGS. 6 and 12 .

As shown in FIGS. 13 and 14 , in some embodiments one or more removablesutures 160 (e.g., Kevlar® sutures) can extend through one or morelumens defined within the wall thickness of the balloon member deliveryshaft 124. In the depicted embodiment, two removable sutures 160 areincluded. The two removable sutures 160 form loops at the distal endportion of the balloon member delivery shaft 124, and the two free endsof the two removable sutures 160 are accessible to the practitioner P(FIG. 1 ) at the proximal end of the kyphoplasty system 100.

Also referring to FIGS. 15 and 16 , the balloon shaft 123 can define oneor more suture attachment features 125 by which the removable sutures160 can be attached to the balloon implant member 122. In the depictedembodiment, the one or more suture attachment features 125 are twoopenings in the balloon shaft 123. The removable sutures 160 can bethreaded through (looped through) the two openings in the balloon shaft123.

In the depicted embodiment, a proximal end portion of the balloon shaft123 (a portion that includes the two openings 125) extends into acounter-bore at the distal end of the balloon member delivery shaft 124(where the loops of the two removable sutures 160 reside). The loops ofthe two removable sutures 160 can pass through the two openings 125 inthe balloon shaft 123. Then, when the practitioner P desires to detachthe balloon member delivery shaft 124 from the balloon implant member122 (as per step 280 of the balloon kyphoplasty procedure 200), thepractitioner P can cut the two removable sutures 160 at the proximalends thereof (if necessary) and pull on one free end portion of each ofthe two removable sutures 160. When a sufficient amount of pulling ofthe two removable sutures 160 is completed, the two removable sutures160 will become detached from the suture attachment features 125 (e.g.,the two openings 125). Then, as illustrated in FIGS. 15 and 16 , thepractitioner P can withdraw the balloon member delivery shaft 124 whileleaving the balloon implant member 122 implanted in the vertebral bodycavity 12 (e.g., as depicted in FIG. 3 ).

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of thedisclosed technology or of what may be claimed, but rather asdescriptions of features that may be specific to particular embodimentsof particular disclosed technologies. Certain features that aredescribed in this specification in the context of separate embodimentscan also be implemented in combination in a single embodiment in part orin whole. Conversely, various features that are described in the contextof a single embodiment can also be implemented in multiple embodimentsseparately or in any suitable subcombination.

Moreover, although features may be described herein as acting in certaincombinations and/or initially claimed as such, one or more features froma claimed combination can in some cases be excised from the combination,and the claimed combination may be directed to a subcombination orvariation of a subcombination.

Similarly, while operations may be described in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order or in sequential order, or that all operationsbe performed, to achieve desirable results. Particular embodiments ofthe subject matter have been described. Other embodiments are within thescope of the following claims.

What is claimed is:
 1. A kyphoplasty system comprising: a balloonimplant member comprising a balloon mounted on a balloon shaft; and aballoon member delivery shaft that is releasably attached to the balloonshaft, wherein the balloon shaft and the balloon member delivery shaftjointly define a single lumen that ends at an open distal end defined bythe balloon shaft, wherein the balloon shaft also defines one or moreapertures that provide fluid communication between an interior of theballoon shaft and an interior of the balloon, an inflation plungerdefining a second lumen, the inflation plunger configured to slidinglyengage in the interior of the balloon shaft and to convey via the secondlumen an inflation medium to inflate the balloon, wherein a distal endportion of the inflation plunger defines one or more inflation aperturesthat allow the inflation medium to exit the second lumen, and whereinthe distal end portion of the inflation plunger includes a first seallocated proximal of the one or more inflation apertures, and wherein thedistal end portion of the inflation plunger includes a second seallocated distal of the one or more inflation apertures.
 2. A kyphoplastymethod comprising: advancing a kyphoplasty system to position a balloonimplant member of the kyphoplasty system in a vertebral body cavity, thekyphoplasty system comprising: the balloon implant member comprising aballoon mounted on a balloon shaft, and a balloon member delivery shaftthat is releasably attached to the balloon shaft, wherein the balloonshaft and the balloon member delivery shaft jointly define a singlelumen that ends at an open distal end defined by the balloon shaft;expanding the balloon while the balloon is in the vertebral body cavity;and after expanding the balloon, injecting filler material into thevertebral body cavity through the single lumen.
 3. The kyphoplastymethod of claim 2, further comprising: after injecting filler material,releasing the balloon implant member from the balloon member deliveryshaft; and withdrawing the balloon member delivery shaft while theballoon implant member remains in the vertebral body cavity.
 4. Thekyphoplasty method of claim 2, wherein said expanding the balloon whilethe balloon is in vertebral body cavity comprises: slidingly insertingan inflation plunger in the single lumen jointly defined by the balloonshaft and the balloon member delivery; and delivering an inflationmedium into an interior of the balloon via a second lumen defined by theinflation plunger.
 5. The kyphoplasty method of claim 4, wherein saidslidingly inserting the inflation plunger comprises aligning one or moreinflation plunger apertures of the inflation plunger with acorresponding one or more input ports along a circumferential wall ofthe balloon shaft.
 6. The kyphoplasty method of claim 5, wherein saidexpanding the balloon while the balloon is in vertebral body cavityfurther comprises: injecting the inflation medium from an interior ofthe inflation plunger, through the one or more inflation plungerapertures aligned with the corresponding one or more input ports alongthe circumferential wall of the balloon shaft, and into the interior ofthe balloon of the kyphoplasty system.
 7. The kyphoplasty method ofclaim 6, wherein a distal end of the balloon member delivery shaft isreleasably and threadably mated with a proximal end of the balloon shaftduring said advancing the kyphoplasty system to position the balloonimplant member of the kyphoplasty system in the vertebral body cavity.8. The kyphoplasty method of claim 7, further comprising detaching thedistal end of the balloon member delivery shaft from the proximal endthe balloon shaft both after said expanding the balloon and after saidinjecting filler material.
 9. The kyphoplasty method of claim 2, furthercomprising: prior to said advancing the kyphoplasty system to positionthe balloon implant member of the kyphoplasty system in the vertebralbody cavity, advancing a bone introducer needle adjacent to thevertebral body cavity; and inserting the balloon implant member into thevertebral body cavity through the bone introducer needle.
 10. Thekyphoplasty method of claim 9, wherein during said inserting the balloonimplant member into the vertebral body cavity through the boneintroducer needle, a distal end of the balloon member delivery shaft isreleasably and threadably mated with a proximal end of the balloonshaft.
 11. The kyphoplasty method of claim 2, wherein during saidexpanding the balloon while the balloon is in the vertebral body cavity,an inflation plunger of the kyphoplasty system is releasably sealedagainst an interior surface of the single lumen jointly defined by theballoon shaft and the balloon member delivery in a position so that atleast one inflation plunger aperture of inflation plunger is alignedwith a corresponding input port along a circumferential wall of theballoon shaft.
 12. A kyphoplasty system comprising: a balloon implantmember comprising a balloon coaxially mounted on a balloon shaft; and aballoon member delivery shaft having a distal end that is releasably andthreadably attached to a proximal end the balloon shaft, wherein theballoon shaft and the balloon member delivery shaft jointly define acentral lumen that ends at an open distal end defined by the balloonshaft; and an inflation plunger configured to convey an inflation mediumto inflate the balloon and to slidingly insert into the central lumenjointly defined by the balloon shaft and the balloon member deliveryshaft so that one or more inflation plunger apertures of the inflationplunger align with a corresponding one or more input ports along acircumferential wall of the balloon shaft, wherein an exterior of theinflation plunger releasably seals against the central lumen jointlydefined by the balloon shaft and the balloon member delivery shaft whenthe inflation plunger conveys the inflation medium to an interior of theballoon.
 13. The kyphoplasty system of claim 12, wherein the balloonmember delivery shaft is configured to deliver the balloon implantmember into a vertebral body while the distal end of the balloon memberdelivery shaft is releasably and threadably mated with a proximal end ofthe balloon shaft.
 14. The kyphoplasty system of claim 13, wherein thedistal end of the balloon member delivery shaft is detachable from theproximal end the balloon shaft while the inflation medium is arranged inthe interior of the balloon of the balloon implant member in thevertebral body.
 15. The kyphoplasty system of claim 12, wherein each ofthe corresponding one or more input ports along the circumferential wallof the balloon shaft includes a one-way valve to seal the inflationmedium in the interior of the balloon.
 16. The kyphoplasty system ofclaim 12, wherein the balloon shaft is coaxially aligned and positionedthrough the interior of the balloon so that the balloon shaft extendsdistally of a distal-most end of the balloon and proximally of aproximal-most end the balloon.